<template>
  <div class="todo-footer" v-show="numTotal>0">
    <label>
      <input type="checkbox" v-model="allDone"/>
    </label>
    <span>
          <span>已完成{{ numDone }}</span> / 全部{{ numTotal }}
        </span>
    <button class="btn btn-danger" @click="clearAllDoneTask">清除已完成任务</button>
  </div>
</template>

<script>
export default {
  name: "MyFooter",
  data() {
    return {}
  },
  props: ['tasks'],
  computed: {
    numTotal() {
      return this.tasks.length;
    },
    numDone() {
      return this.tasks.reduce((pre, cur) => {
        return pre + (cur.done ? 1 : 0);
      }, 0);
    },
    allDone: {
      get() {
        return this.numDone === this.numTotal && this.numTotal > 0;
      },
      set(value) {
        if (value) {
          this.$emit('appModifyAll', true);
        } else {
          this.$emit('appModifyAll', false);
        }
      }
    }
  },
  components: {},
  methods: {
    clearAllDoneTask() {
      if (confirm("是否要清空所有已完成任务？")) {
        this.$emit('appClearAllDoneTask');
      }
    }
  },
  mixins: [],
  watch: {},
  filters: {},
  directives: {}
}
</script>

<style scoped>
/*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}
</style>